Can we avoid recertification? 1

[sbush]

We have an existing ASME U-stamped vessel in the field and the 24" hinged manway needs to be replaced due to corrosion on the sealing surfaces between the ring and hinged cover. The manway ring protudes approximately 4" from the exterior of the vessel. Can we cut off 1" of the top portion of the ring to remove the old cover and weld on a new ring with a new cover without having to have the tank recertified and inspected?

 

[vesselguy]

Maybe others could, but I don't understand what you're talking about "manway ring" on the exterior of the hinged manway cover. However, it might irrelevent to your question.

As long as you are not welding directly to or modifying the pressure containment envelope of the pressure vessel, you do not need to "recertify" it.

FYI, the term "tank" refers to an atmospheric tanks. Pressure vessels should be refer to as a "vessel" so there is no confusion in a discussion.

 

[sbush]

Vesselguy,

Thanks for your answer. In this case, we would be modifying the pressure containment envelope.

We purchase our manways from LA Boiler Works and "ring" is a term they use. The ring is the nozzle portion of the manway that is welded to the vessel. The portion of the ring that protrudes out from the vessel comes from LABW already fitted with swing-away bolts, o-ring gasket, and domed cover with hinge.

 

[lostsailor]

sbush,
What you are proposing is a repair as defined by the National Board Inspection Code 2004 Edition 2006 Addenda
paragraphs RC-1020,RC-1050, and Appendix 6-2000(a) or (h). In order to maintain the Code integrity of the vessel and associated paper trail, the material should be procured and work performed by an R or U stamp holder with appropriate scope.
Regards,
RLS

 

[dtn6770]

Some jurisdictions don't require NBIC (R) repairs. In cases like that, API 510 can be an alternative repair/alteration "code" and will have specific requirements.

 

[vesselguy]

sbush,

Now, I see. You are cutting off the nozzle neck and butt welding a new flange on. In that case, do what lostsailor specified. If your vessel was post weld heat treated, then you need to do the same after the repair weld. Hydrotesting is also required after completion.